Adherent water vapour permeable air and moisture barrier sheet material

Abstract

A water vapour-permeable building sheet material, that may be adhered in overlapping relationship against a building structure, includes a water vapour permeable membrane having first and second opposing surfaces, wherein the surface energy of the second opposing surface is less than 35 mN/m; an adhesive layer that is vapour permeable, applied to the first face of the membrane; and an adhesive region applied to the second opposing surface. Two segments of the sheet material may be placed in overlapping relationship so that adhesive in the adhesive layer applied to the first face of the membrane of one of two segments adheres to the adhesive region applied to the second opposing face of the other of the two segments to form a substantially air impermeable boundary between the two segments, when overlapping, preventing lateral migration of air between the two segments. A building envelope may be so formed.

What is claimed is: 
     
       1. A water vapour-permeable building sheet material comprising segments installed in overlapping relationship against a building structure, wherein each of said segments comprises:
 a water vapour permeable membrane having first and second opposing surfaces, wherein the surface energy of said second opposing surface is less than 35 mN/m; 
 an adhesive layer that is vapour permeable, and pre-applied to substantially the entirety of said first opposing surface prior to installation of the water vapour permeable membrane; 
 an adhesive region comprising at least one strip of adhesive pre-applied to the second opposing surface, to extend lengthwise parallel and proximate its edge prior to installation of the water vapour preamble membrane; 
 wherein at least one strip of adhesive of said adhesive region of a first segment of said sheet material bonds to the adhesive layer of a second segment of said sheet material when said second segment of said sheet material is placed in overlapping relationship with the at least one strip of adhesive of said adhesive region of said first segment, without precise alignment, to form a substantially air impermeable boundary between said first segment and said second segment, preventing lateral migration of air between said first segment and said second segment. 
 
     
     
       2. The sheet material of  claim 1 , wherein said adhesive layer comprises an adhesive pre-applied discontinuously to said first opposing surface to provide uncovered regions, exposing said water vapour permeable membrane to allow water vapour to permeate therethrough. 
     
     
       3. The sheet material of  claim 2 , wherein said adhesive layer is applied in a geometric pattern to cover between 1% and 99% of said first opposing surface. 
     
     
       4. The sheet material of  claim 1 , wherein said adhesive layer comprises a hot melt adhesive. 
     
     
       5. The sheet material of  claim 4 , wherein said adhesive layer comprises at least one of a solvent based adhesive; a polymer dispersion adhesives; a pressure sensitive adhesives; a butyl based adhesive; an acrylate based polymer adhesive; a hot-melt adhesive; a reactive adhesive; a natural adhesive; or an acrylic polymer. 
     
     
       6. The sheet material of  claim 1 , wherein said adhesive region comprises a strip of adhesive pre-applied generally parallel to a lengthwise extending edge of said sheet material. 
     
     
       7. The sheet material of  claim 1 , wherein said adhesive region comprises a plurality of parallel strips of adhesive. 
     
     
       8. The sheet material of  claim 1 , wherein said adhesive region comprises a hot melt adhesive. 
     
     
       9. The sheet material of  claim 1 , further comprising a removable film, coating said adhesive layer on said first opposing surface. 
     
     
       10. The sheet material of  claim 1 , further comprising a removable film, coating said adhesive region on said second opposing surface. 
     
     
       11. The sheet material of  claim 1 , wherein said second opposing surface is formed of one of Polyethylene; Polypropylene (PP). 
     
     
       12. The sheet material of  claim 1 , wherein said water vapour permeable membrane comprises a spun-bond layer. 
     
     
       13. The sheet material of  claim 1 , wherein said water vapour permeable membrane comprises a porous film. 
     
     
       14. The sheet material of  claim 1 , wherein said water vapour permeable membrane comprises a second spun bond layer. 
     
     
       15. The sheet material of  claim 1 , wherein the surface tension of said second opposing surface is less than 32 mN/m. 
     
     
       16. A building envelope comprising a plurality of sheet segments of sheet material each of said sheet segments comprising
 a water vapour permeable membrane having first and second opposing surfaces; 
 an adhesive pre-applied discontinuously to said first opposing surface of said water vapour permeable membrane to provide uncovered regions, exposing said water vapour permeable membrane to allow water vapour to permeate therethrough; 
 an adhesive region pre-applied to the second opposing surface, wherein the surface energy of said second opposing surface is less than 35 mN/m; 
 wherein said sheet segments of said sheet material are placed in overlapping relationship on a building structure such that the adhesive pre-applied to said first opposing surface of a first of said sheet segments mates and bonds with the adhesive region pre-applied to said second opposing surface of an adjacent one of said sheet segments to form a substantially air impermeable boundary between said adjacent sheet segments to prevent lateral migration of air between said adjacent sheet segments, so that the air leakage of said building envelope does not exceed 0.2 I/s/m 2  at a pressure difference of 75 Pa after wind pressure conditioning when tested in accordance with ASTM E-2357. 
 
     
     
       17. The building envelope of  claim 16 , wherein said adhesive is applied in a geometric pattern to cover between 1% and 99% of said first opposing surface. 
     
     
       18. The building envelope of  claim 17 , wherein said adhesive comprises at least one of a solvent based adhesive; a polymer dispersion adhesive; a pressure sensitive adhesives; a butyl based adhesive; an acrylate based polymer adhesive; a hot-melt adhesive; a reactive adhesive; a natural adhesive; or an acrylic polymer. 
     
     
       19. The building envelope of  claim 16 , wherein said adhesive region comprises a strip of adhesive generally parallel to a lengthwise extending edge of said sheet material. 
     
     
       20. A water vapour-permeable building sheet material comprising segments adhered in overlapping relationship against a building structure, wherein each of said segments comprises:
 a water vapour permeable membrane having first and second opposing surfaces, wherein the surface energy of said second opposing surface is less than 35 mN/m; 
 an adhesive layer that is vapour permeable, pre-applied to cover the area of said first opposing surface of said water vapour permeable membrane, with between 1% and 99% of adhesive; 
 an adhesive region pre-applied to the second opposing surface generally parallel to a lengthwise extending edge of said sheet material; 
 a first removable film, coating said adhesive on said first opposing surface; 
 a second removable film, coating said adhesive region on said second opposing surface; 
 wherein at least one strip of said adhesive region of a first segment of said sheet material bonds to the adhesive layer of a second segment of said sheet material when said second segment of said sheet material is placed in overlapping relationship with the at least one strip of said adhesive region of said first segment, without precise alignment, to form a substantially air impermeable boundary between said first segment and said second segment, preventing lateral migration of air between said first segment and said second segment.